Morphological characteristics of endosperm in different regions of maize kernels with different vitreousness

Abstract

The vitreous and floury endosperms have regional distributions in maize kernels, and influence their qualities and applications. In this study, the whole transverse and longitudinal sections of maize mature dent, flint, and pop kernels were observed to reveal and compare the morphological characteristics of cell, starch, and protein in different regions of endosperm. The shape and size of cells had significant differences in different regions of dent and flint maize endosperms, but had no relationship with vitreous and floury texture. Popcorn had homogeneously polygonal cells in whole endosperm. The vitreous endosperm in middle and central regions of kernel had polygonal starch granules with large size and that close to aleurone cells had spherical granules with small size, but the floury endosperm had only spherical granules with different sizes. The shape and size of starch granules did not directly determine the texture of vitreous and floury endosperm. The storage protein was distributed regionally in endosperm, and its content and spatial distribution was related with vitreous endosperm. The above results not only enriched our knowledge of vitreous and floury endosperms of maize, but also provided some information for quality breeding and applications of maize kernels with different vitreousness.